a) \(\left(\frac{-5}{11}\right) \cdot \frac{7}{15} \cdot \frac{11}{-5} \cdot (-30)\);

b) \(\left(\frac{-1}{3}\right) \cdot \frac{15}{19} \cdot \frac{38}{45}\);

Multiply the fractions:
[tex]\left(\frac{-5}{11}\right) \cdot \frac{11}{-5} = 1[/tex]
Here, [tex]\frac{-5}{11} \cdot \frac{11}{-5}[/tex] results in a reciprocated multiplication, which equals 1.
Substitute back into the expression:
[tex]1 \cdot \frac{7}{15} \cdot (-30)[/tex]
Multiply fractions with integers:
[tex]\frac{7}{15} \cdot (-30) = \frac{7 \cdot (-30)}{15} = \frac{-210}{15} = -14[/tex]

Thus, the final result for part a is [tex]-14[/tex].

b) [tex]\left(\frac{-1}{3}\right) \cdot \frac{15}{19} \cdot \frac{38}{45}[/tex]

Follow these steps to solve it:

Multiply the fractions:
- Multiply the first two fractions:
  [tex]\left(\frac{-1}{3}\right) \cdot \frac{15}{19} = \frac{-1 \cdot 15}{3 \cdot 19} = \frac{-15}{57}[/tex]
- Simplify [tex]\frac{-15}{57}[/tex] by their greatest common divisor, which is 3:
  [tex]\frac{-15}{57} = \frac{-5}{19}[/tex]
Continue multiplying with the next fraction:
[tex]\frac{-5}{19} \cdot \frac{38}{45} = \frac{-5 \cdot 38}{19 \cdot 45} = \frac{-190}{855}[/tex]
Simplify if possible:
Simplify by dividing numerator and denominator by their greatest common divisor, which is 5:
[tex]\frac{-190}{855} = \frac{-38}{171}[/tex]

Thus, the final result for part b is [tex]\frac{-38}{171}[/tex].

a) \(\left(\frac{-5}{11}\right) \cdot \frac{7}{15} \cdot \frac{11}{-5} \cdot (-30)\);b) \(\left(\frac{-1}{3}\right) \cdot \frac{15}{19} \cdot \frac{38}{45}\);